We are creating organization chart using GoJS where user can drag and drop nodes from Pallete (something similar http://gojs.net/latest/samples/flowchart.html) in chart. While drag-drop on valid node is working fine, I need help in following :
User should not be able to drop node on blank area of chart, and should be able to drop only on existing node. If user tries to drop I need to delete and show alert.
When user drags node from Pallete and brings it over a node on chart, I need to highlight node where it will be added.